The present invention relates generally to farm implements, and more particularly to a farm implement which can be attached to a farm vehicle for loosening or breaking up the soil in preparation for agricultural use.
Farm implements which can be attached to farm vehicles for breaking up the soil as the vehicle is driven over the surface of a field are, of course, well known and include plows and choppers which have either stationary fingers for engaging and ripping up the soil as the vehicle is advanced, or chisel type loosening bits suspended for swinging movement and which carry blades generally inclined to the direction of travel. The advantage of using the swinging loosening bits is that the soil can be loosened and aerated while preserving its natural stratification. In addition, the swinging movement of the loosening bits tend to assist in the forward advance of the implement along the surface of the ground and thus minimizes the power required to pull the implement. This advantage is a result of each loosening bit resting on the surface of the soil during at least a portion of time that the implement is being advanced rather than constantly engaging the soil and presenting resistance to forward movement.
One such type of farm implement for loosening soil having loosening bits suspended for swinging movement, is shown in German Pat. No. 1 782 037. In this German patent the loosening bits are carried for vertical adjustment on swing levers which are suspended in a side-by-side arrangement on a supporting frame. The various swing levers are driven for swinging movement by a cross-shaft which, in turn, is driven through a miter gear connection from a power output of the farm vehicle. The cross-shaft carries spaced eccentric discs with connecting rods positioned between the discs and supporting the swing levers. In this manner, the loosening bits are caused to move back and forth in a circular path as the farm vehicle drives the cross-shaft. The center of the circular path is formed by the upper pivot point of the swing levers on the supporting frame.
The swinging back and forth movement adequately breaks up the soil, however, it has a tendency to force clumps or clods of soil out of the ground without sufficiently crushing such clumps or clods. Also, because each loosening bit will simply rest in the soil during a portion of the forward movement of the vehicle and the apparatus, it will effectively be moving in a return direction at a speed equal to the forward travel of the vehicle resulting in a disproportionately high power consumption on the power output of the vehicle. Additionally, the stationary positioning of the loosening bits on the ground tends to cause the entire implement to rise slightly as it passes over the loosening bit. This is particularly true when attempting to loosen very firm soil and to a somewhat lesser degree when the soil is relatively soft, in which case the loosening bit will tend to sink into the soil as the implement rides over it. This results in uneven and unsteady operation of the implement as it rides over the surface of the soil.
Therefore, it is the primary object of the invention to provide an apparatus for loosening soil, intended for attachment to a farm vehicle, which has movable loosening bits for engaging and breaking up the soil in a manner which produces more complete crushing of the soil and which minimizes power consumption by the farm vehicle required for driving the implement.